1. Field of the Invention
The present invention relates to a locking device for a retractable handle of wheeled luggage and more particularly to such a locking device for handle assembly with multiple stages.
2. Description of Related Art
Typically, a single locking device is provided in the retractable handle for controlling the handle in a retracted position and an extended position. That is, the retractable handle may be extended to a maximum length when towing on the ground by traveler as well as retracted into a minimum length (i.e., rested on the top of luggage) appropriate for stowage or transport. It is known that luggage equipped with a retractable handle is very popular among travelers. Thus many types of luggage with retractable handle are commercially available in which most of the retractable handles are two stages, i.e., the handle either in a retracted position with minimum length or in an extended position with maximum length. This may be found in the disclosure of U.S. Pat. No. 5,581,846. A few of the retractable handles have a multiple retaining slots design. This may be found in the disclosure of U.S. Pat. No. 5,628,088. The multiple retaining slots design aims at providing a variable handle length when towing along the ground in order to accommodate different heights of people. However, it is also found that luggage have a variety of sizes and heights. The multiple retaining slots design can not completely solve the problems associated with two stages handle. This is because an optimum retractable handle should comply with a plurality of factors such as sex, age, and height of user in no connection with whether retractable handle is two stages or has multiple retaining slots as detailed below.
Various designs of locking devices for handle assembly with multiple retaining slots have been found in a search as follows: Taiwanese Patent Published No. 362,404 entitled xe2x80x9cActivation Mechanism for Retractable Handle with Multiple Retaining Slots of Luggagexe2x80x9d and No. 368,815 entitled xe2x80x9cImproved Activation Mechanism for Retractable Handle with Multiple Retaining Slots of Luggagexe2x80x9d. But these are unsatisfactory for the purpose for which the invention is concerned for the following reasons:
1. Complex in components, for example, an additional central member 19, a lower positioning member 63 of sub-assembly 60, and other associated members are provided.
2. Time consuming in assembly.
3. A horizontal component force is applied on the slope when lock blocks (or pins) are activated by slanted guide groove. This causes additional drawbacks in addition to those described above. In detail, the ratio of extendible maximum length to retractable minimum length is significantly lowered due to the implementation of multiple-segment longitudinal slanted guide groove. This limits the effective length of extended handle. Thus improvement is desirable.
It is therefore an object of the present invention to provide a locking device for handle assembly with multiple stages for significantly increasing the ratio of extendible maximum length to retractable minimum length of handle such that a predetermined extendible length is achievable.
It is another object of the present invention to provide a locking device for handle assembly with multiple stages wherein lock member of first locking means is provided at the bottom of first housing of the first locking means capable of directly moving into the lock hole of the second locking means so as to cause lock pin of the second locking means to become disengaged; and lock member of second locking means is capable of directly moving into the lock hole of the third locking means so as to cause lock pin of the third locking means to become disengaged. As such, lock member of higher locking means is capable of directly moving into the lock hole of the next lower locking means so as to cause lock pin of the next lower locking means to become disengaged. Further, there is no horizontal component force created on the slope as occurred in the prior art because the lock member of the higher locking means directly inserts into the lock hole of next lower locking means as well as higher locking means and next lower locking means are engaged in a planar surface. This ensures that there is no gap between the higher and next lower locking means such that the handle grip of the fully retracted handle may rest on the bezel.
To achieve the above and other objects, the present invention provides a locking device for handle assembly with multiple stages comprising:
a first sliding tube; a first locking means detachably attached to the bottom of the first sliding tube; a second sliding tube for allowing the first sliding tube to slidingly move therein having an upper hole and a lower hole; a second locking means detachably attached to the bottom of the second sliding tube; a third sliding tube for allowing the second sliding tube to slidingly move therein having an upper hole and a lower hole; a third locking means detachably attached to the bottom of the third sliding tube; a support tube for allowing the third sliding tube to slidingly move therein having an upper hole and a lower hole; and a first connecting means connected between a push button and the first locking means.
Whereby the handle is retracted when the push button is not pressed, the first sliding tube is received in the second sliding tube, the second sliding tube is received in the third sliding, the third sliding tube is received in the support tube, the lock projection of the first locking means is engaged with the lower hole of the second sliding tube, the bottom of the first locking means is biased against the top of the sliding block of the second locking means so as to move the lock member of the first locking means into the lock hole of the second locking means to cause the first end of the lock pin of the second locking means to retract into the third sliding tube, the second end of the lock pin of the second locking means to extend into the lower hole of the third sliding tube, the bottom of the second locking means is biased against the top of the sliding block of the third locking means so as to move the lock member of the second locking means into the lock hole of the third locking means to cause the first end of the lock-pin of the third locking means to retract into the support tube, and the second end of the lock pin of the third locking means to extend into the lower hole of the support tube, whereby the handle is locked in a retracted position.
The push button is pressed. Then handle is pulled upward to cause the first locking means to move up so as to move the lock pin of the first locking means into lower hole of the second sliding tube. Grasp handle grip to pull first sliding tube upward so as to move the lock pin of the second locking means into the upper hole of the third locking means for disengaging the lock member on the bottom of first locking means from lock hole of the second locking means. Then the second end of the lock pin of the second locking means retracts to become disengaged to cause the second locking means to move up as the second sliding tube and the first sliding tube move up together until the second lock pin comes into contact with upper hole of the third sliding tube and locks therein. At the same time, the lock member on the bottom of second locking means disengages from the lock hole of the third locking means. Then the second end of the lock pin of the second locking means retracts to become disengaged to cause the third locking means to move up as the third sliding tube and the second sliding tube move up together until the third lock pin comes into contact with upper hole of the support tube and locks therein. Now handle is in a fully extended position for allowing luggage to be towed along the ground.
In one aspect of the invention the locking device for handle assembly with multiple stages is provided wherein the locking device comprises a longitudinal lock hole, a lateral lock hole, and a lock pin at the bottom. Further, longitudinal lock hole and lateral lock hole are in communication each other. Longitudinal lock hole has a lock block being movable to either right or left to lock thereto. As such, lock block is locked in upper hole of the corresponding tube when handle is pulled up to its maximum length, while lock block is locked in lower hole of the corresponding tube when handle is pushed down to its minimum length.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.